In the semiconductor industry, structure wafers or product wafers are often temporarily bonded onto carrier wafers or first substrates in order to be able to handle them. After processing of the product wafers, they should be removed from the first substrate as simply, promptly, economically and cleanly as possible. The method which is most often used for bonding of product wafers on a carrier wafer is the application of an adhesion layer to one of the two substrates (or both substrates) and contact-making under pressure. When debonding, the carrier wafer is debonded from the product wafer after reducing the adhesion force of the adhesive (temperature, UV radiation, etc.), for example by parallel displacement of the wafers against one another. The wafers are held by so-called chucks by negative pressure. Very often wafers are also permanently connected by fusion bonding (mainly van der Waals forces) and subsequent annealing (heating above the recrystallization temperature).
During debonding a plurality of critical factors must be considered; the highest priority consists in exposing the brittle product wafers, which are very expensive due to preprocessing, to as little stress as possible so as not to damage them. On the other hand, the debonding of the first substrate should take place economically and promptly with minimum possible energy expenditure. In a plurality of known debonding processes, it is necessary, especially for dissolving the adhesion properties of the adhesion layer between the wafers, to heat up the stack of carrier wafers and structure wafers/product wafers to a temperature which is specific to the adhesive.
The object of this invention is to develop generic devices and methods for debonding from the first substrates wherein careful, and at the same time much faster, debonding is enabled. At the same time, the energy consumption will be reduced.
Advantageous developments of the invention are given in the dependent claims. All combinations of at least two of the features given in the specification, the claims and/or the figures also fall within the framework of the invention. At the given value ranges values which lie within the indicated boundaries will also be considered disclosed as boundary values and will be claimed in any combination.